Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/35—Optical coupling means having switching means
  • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
  • G02B6/3582—Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/262—Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/32—Optical coupling means having lens focusing means positioned between opposed fibre ends
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/36—Mechanical coupling means
  • G02B6/3628—Mechanical coupling means for mounting fibres to supporting carriers
  • G02B6/3632—Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means
  • G02B6/3636—Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means the mechanical coupling means being grooves
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/264—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/264—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting
  • G02B6/266—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting the optical element being an attenuator
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/35—Optical coupling means having switching means
  • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/35—Optical coupling means having switching means
  • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
  • G02B6/3512—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being reflective, e.g. mirror
  • G02B6/3518—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being reflective, e.g. mirror the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/35—Optical coupling means having switching means
  • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
  • G02B6/3524—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being refractive
  • G02B6/3528—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being refractive the optical element being a prism
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/35—Optical coupling means having switching means
  • G02B6/354—Switching arrangements, i.e. number of input/output ports and interconnection types
  • G02B6/3544—2D constellations, i.e. with switching elements and switched beams located in a plane
  • G02B6/3546—NxM switch, i.e. a regular array of switches elements of matrix type constellation
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/36—Mechanical coupling means
  • G02B6/3628—Mechanical coupling means for mounting fibres to supporting carriers
  • G02B6/3632—Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means
  • G02B6/3636—Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means the mechanical coupling means being grooves
  • G02B6/364—Mechanical coupling means for mounting fibres to supporting carriers characterised by the cross-sectional shape of the mechanical coupling means the mechanical coupling means being grooves inverted grooves, e.g. dovetails

Definitions

• This invention relates to optical devices and methods of manufacture. More particularly, the invention pertains to devices and methods of making such devices in which a plurality of lensed fibers are arranged in a curvilinear pattern.
• Optical fiber and lens arrays are used to couple light between optical fibers and optical devices in optical communication systems.
• Conventional optical fiber and lens arrays typically include an array of fibers arranged in a silicon v-groove positioning element, and the fiber ends are abutted to a lens array, which can be molded from an appropriate polymeric material.
• One limitation of this type of fiber and lens array is that since the lenses and fibers are separate elements, it is difficult to optimally align the core region of the optical fiber with the lens, which results in insertion loss.
• Lensed optical fibers are devices that include a fiber having a lens formed on the end of the fiber.
• the assignee of the present invention manufactures lensed fibers under the OptiFocusTM product line, which includes lensed fibers for collimating, focusing, imaging and condensing light.
• One type of OptiFocusTM lensed optical fiber includes monolithic devices that comprise a lens having a lens end portion attached to an end portion of a fiber.
• Some lensed fibers include a neck portion surrounding and end portion of the fiber, and the diameter of the neck portion of the lens is greater than the diameter of the fiber.
• lensed fibers examples include, but are not limited to, collimating lensed fibers, focusing lensed fibers and tapered lensed fibers.
• Collimating lensed fibers are up to four times smaller than typical fiber-lens devices, and lensed fibers do not require any alignment of the lens to the fiber.
• Focusing lensed fibers are capable of focusing light beam sizes down to about six microns, with long working distances.
• Tapered lensed fibers include a high precision, tapered lens for high numerical aperture applications with short working distances.
• N-grooves are used as fiber positioning elements. N-grooves are formed in a pair of upper and lower silicon substrates and fibers are placed in these grooves. The upper and lower substrates sandwich the fibers and hold the fibers in the grooves.
• N-groove devices have several limitations. For example, once a N-groove is fabricated, it serves to position the optical fiber only relative to the silicon substrate. The end of the fiber, which includes the lens, must still be positioned relative to other optical elements in the system.
• N-grooves for positioning lensed fibers are sized to hold the fiber, but the N-groove is too small to hold the lens portion of the lensed fiber.
• An alignment method and apparatus is needed to hold both the fiber portion and the lens portion of the lensed fiber in position.
• Various embodiments of the invention relate to methods and articles for positioning arrays of lensed optical fibers and optical devices including such arrays.
• the present invention provides relatively simple and inexpensive methods for positioning lensed optical fiber elements and articles including lensed optical fiber elements arranged in curvilinear arrays.
• the methods and articles do not require adhesives or expensive micropositioning of the fibers.
• the methods and apparatus can precisely position and hold both the lens portion and the fiber portion of lensed optical fibers.
• FIG. 1 is a side view of a substrate including fiber and lens gripping elements holding a lensed fiber;
• FIG. 2 is an edge view of a gripping element
• FIG. 3 is an edge view of a gripping element including an optical fiber disposed between a groove of the gripping element
• FIG. 4 is a top view of an optical device including an array of lensed fibers circularly arranged around an optical device;
• FIG. 5 is a top view of an optical device including an array of lensed fibers arranged in a semi-circle around an optical element.
• the various embodiments of the present invention provide methods and articles for positioning lensed fibers in arrays.
• the term "lensed fiber” refers to an optical fiber that includes a lens formed on at least one end of a fiber.
• the lens includes generally cylindrical neck portion integrally attached to or surrounding an end portion of the fiber and a lens portion or lens surface.
• the lens portion or lens surface can be a variety of shapes, but in preferred embodiments, the lens surface is convex-shaped.
• the methods and articles of the present invention are useful for making optical waveguide devices includes arrays of optical fibers and other optical elements that include but are not limited to prisms, switches, waveguides, filters and polarizers.
• the positioning elements for the lenses and the fibers and other optical elements can all be arranged on a common substrate.
• United States patent numbers 6,266,472 and 5,359,687 both of which are incorporated herein by reference, describe polymer microstructures and methods of manufacturing such microstructures for gripping optical fibers.
• United States patent number 5,359,687 the polymer microstructures formed on a substrate are used to grip optical fibers and position these fibers with respect to a waveguide disposed on the substrate.
• United States patent number 6,266,472 discloses polymer gripping elements that are used in splicing optical fibers.
• 5,359,687 and 6,266,472 are suitable for gripping optical fibers not physically connected to any other elements, lensed fibers require further stabilization to securely hold and align the lens portion of a lensed fiber.
• the various embodiments of the present provide means for holding and precisely aligning both the fiber portion and the lens portion of individual lensed fibers in arrays, enabling the production of a wide variety of optical devices.
• Certain embodiments of the invention relate to articles for positioning a plurality of lensed optical fibers, wherein each lensed optical fiber has an optical fiber portion and a lens portion.
• the article includes a plurality of fiber gripping elements on arranged in a curvilinear pattern on a substrate, each gripping element including a pair of elastomeric side walls defining a groove therebetween sized to hold the optical fiber portion of the lensed optical fiber.
• the article further includes a plurality of lens gripping elements arranged in a curvilinear pattern on the substrate, each lens gripping element including a pair of elastomeric side walls defining a groove therebetween sized to hold the lens portion of the lensed optical fiber.
• the lens portion further includes a neck portion and a convex-shaped end portion and the lens gripping element is sized to hold the neck portion.
• the elastomeric sidewalls of the lens gripping element and the fiber gripping element are comprised of a polymer.
• the curvilinear pattern may include a variety of patterns including, but not limited to a semicircle and a circle.
• each of the lensed optical fibers includes an optical path and the article further includes an optical element disposed in at least one of the optical paths of the lensed optical fibers. Suitable optical elements include, but are not limited to, a MEMs mirror, a liquid crystal switch, an electroholographic switch, a prism a polarizer, a switch, a modulator and an attenuator.
• the method includes disposing a plurality of fiber gripping elements in a curvilinear pattern on a substrate, each fiber gripping element including a pair of elastomeric side walls defining a groove therebetween sized to hold the optical fiber portion of the lensed optical fiber.
• the method further includes disposing a plurality of lens gripping elements in a curvilinear pattern on the substrate, each lens gripping element including a pair of elastomeric side walls defining a groove therebetween sized to hold the lens portion of the lensed optical fiber.
• the method includes positioning the fiber portions of the lensed fiber within the fiber gripping elements and positioning lens portions of the lensed fiber within the lens gripping elements.
• each of the optical fibers includes an optical path for transmitting light and the method further includes disposing an optical element in the optical paths.
• a fiber and lens gripping article 10 is shown and includes a substrate 12.
• the substrate 12 can be made from a variety of materials including but not limited to glass, silicon, ceramics and plastics.
• the substrate 12 preferably includes a stepped feature including a lower surface 14 and an upper surface 16.
• the upper surface 16 and the lower surface 16 are planar surfaces.
• At least one fiber gripping element 18, and preferably a plurality of fiber gripping elements 18 are positioned on the upper surface 16 of the substrate 12.
• At least one lens gripping element 20, and preferably a plurality of lens gripping elements are provided on the lower surface 14 of the substrate.
• the lens griping element 20 and the fiber gripping element 18 are preferably arranged collinearly on the substrate 12.
• the fiber gripping elements 18 are sized to firmly hold an optical fiber 22 in position on the substrate.
• the lens gripping elements 20 are sized to firmly hold a lens 24 in place on the substrate.
• the lens 24 includes a convex shaped portion or surface 26 and a neck portion 28 and is integrally formed on an end of the optical fiber 22. It will be understood, however, that the shaped of the lens does not have to be convex and other lens shapes are within the scope of the invention.
• the neck portion 28 of the lens has a diameter that is greater than the diameter of the optical fiber lens.
• the step feature on the substrate 12 provides the upper surface 16 for the fiber to rest on.
• the lower surface 14 provides a surface for the lens neck to rest on.
• the upper surface 16 can be made from the same material as the lower surface 14. Steps can be formed on the substrate by removing a portion of the lower surface 12 of the substrate by techniques including but not limited to grinding or etching such as reactive ion etching. Alternatively, steps can be provided by laminating, injection molding, lithography or printing the step to provide an upper surface 16 on the substrate 12. If the step and upper surface are provided in this manner, the step and upper surface 16 may be made from a material that is different than the material that makes up the lower surface 14. [00025]
• Fig. 2 shows a gripping element 30 in more detail, and it will be understood that the details of the gripping element shown in Fig. 2 pertain to fiber gripping elements and lens gripping elements, except for the differences noted below.
• the gripping element 30 includes laterally spaced elastomeric strips 32 attached to the surface of a substrate 34.
• Each of the elastomeric strips has a base portion 36 attached to a surface of the substrate 34, a top surface 38 which is preferably substantially parallel with the surface of the substrate 34 and side walls 40 which provide a groove 42 between the strips 32.
• a portion of the substrate 34 forms a floor of the groove 42.
• a portion of the substrate surface forms a floor 44 for the gripping element so that the groove has a width near the floor w 2 that is greater than the width wi at the top of the groove.
• the width wi at the top of the groove is less than the diameter d of the fiber or the neck area of the lens.
• the width w 2 at the bottom of the groove is preferably greater than the diameter d of the lens neck or the fiber. It will be understood that fibers having a larger diameter, for example coated fibers versus uncoated fiber, will require a larger groove to accept insertion of the fiber and to hold the fiber in place vertically and horizontally along its axis.
• the neck area of the lens will generally have a larger diameter than the fiber, and therefore the lens grippers will generally have a larger groove width than the fiber grippers.
• the sidewalls of each strip should be sufficiently flat so that each strip contacts the fiber or neck portion of the lens at least at one point so that the gripper exerts a force on the fiber or lens neck generally perpendicular to the fiber axis.
• United States patent number 5,359,687 contains additional details on particular dimensions for common telecommunications fibers.
• the strips that make up the gripping elements are formed using well-known lithographic processes using photopolymerizable compositions and the like.
• a photopolymerizable composition can be substantially uniformly deposited on onto a substrate surface.
• the photopolymerizable composition is then imagewise exposed to actinic radiation using a laser and a computer-controlled stage to expose precise areas of the composition with an ultraviolet laser beam, or a collimated UN lamp together with a photomask having a pattern of substantially transparent and substantially opaque areas.
• the nonimaged areas can then be removed with solvent, while leaving the imaged areas in the form of at least one gripping element on the substrate surface.
• elastomeric strips can be formed by using a soft, flexible embossing tool to pattern the polymerizable composition in the form of at least one gripping element on the substrate surface.
• a soft, flexible embossing tool is commonly made with silicones.
• the composition is then cured and the tool is removed.
• the flexibility of the tool must be sufficient so that it can be removed from the cured polymer without damaging the grippers.
• the polymerizable composition may be cured by various means such as actinic radiation or heat, and should have the viscosity to conform to the raised features of the tool. After removing the tool from the cured composition, at least one gripping element will remain on the substrate, depending on the nature of the pattern.
• the pattern of the tool may include a plurality of gripping elements to provide a substrate for aligning an array of fiber and lenses. Suitable polymeric compositions for making the gripping elements are disclosed in commonly assigned United States patent 6,266,472.
• an optical device 100 includes an array of lensed optical fibers 102, each of the lensed fibers 102 including a fiber portion 104 and a lens that includes a lens surface 106 and a neck portion 108.
• Fiber gripping elements 110 and lens gripping elements 112 are arranged on the surface of a substrate in the desired curvilinear pattern. After the gripping elements 110 and 112 are arranged in the selected pattern, the fibers and lenses are inserted into the gripping elements to provide the array.
• the lensed fibers are arranged in a rotary or circular pattern around an optical element 114, which can be an element for redirecting the direction of light transmitted through the lensed fiber as shown in Fig. 4.
• the optical element can be mounted to the surface of the substrate with an adhesive.
• the optical element could be a prism including multiple thin film filters, a microelectromechanical (MEMs) mirror, an electroholographic grating material, or a liquid crystal switch for redirecting the direction of the transmitted light.
• the device shown in Fig. 4 can function as a router or a switch. [00030] In Fig.
• an optical device 120 which includes a plurality of lensed optical fibers 122 including fiber portions 124 and lens portions that include a lens surfaces 126 and a neck portions 128.
• Fiber gripping elements 130 and lens gripping elements 132 hold the lensed fibers in the desired configuration.
• an optical element 134 is disposed in the light path of the lensed optical fibers 122.
• the optical element can be a switching element such as a MEMS switch, an electroholographic switch or a LCD switch, which can redirect light from individual fibers to other fibers in the array as shown by the arrows 136 and 138.
• the 4 and 5 includes forming a multistep substrate with an embossing tool or by removing portions of a substrate by techniques such as etching or grinding.
• the substrate surfaces on which gripping elements are formed are prepared with an adhesion promoter to enhance bonding of the gripping elements to the substrate surface.
• the gripping elements are formed on the surfaces of the substrate with an embossing tool or photomask and cured with actinic radiation or heat as described in United States patent number 6,266,472.
• the gripping elements should be flexible enough to provide enough elastic strength to deform under applied stress when the fibers of lens necks are inserted into the grooves of the gripping elements.
• a slot is then provided in the substrate by using a saw or laser.
• a filter, a mirror, an attenuator, a modulator, a grating, a polarizer, a switch such as a liquid crystal switch or other optical device is placed in the slot and held in place by an adhesive. If a switching element such as a liquid crystal switch is used as the optical element, the light passing from one array of optical fibers can divert a signal beam from one individual fibers in one array to a fiber in the other array that is not collinear or in line with the fiber in the other array. Lensed optical fibers are then inserted into the gripping elements to form an array of fibers. The fibers are inserted in the fiber gripping elements and the lens neck portions are inserted in the lens gripping elements.
• lensed fiber arrays can be arranged in a curvilinear manner, such as in a circular, semicircular array, parabolic and arrays of other shapes.
• Silicon v-groove technology limits the number of configurations that can be used to position fibers and fiber and lenses in an array because silicon v-grooves are constrained by the crystallographic planes of the material to achieve the v-shaped grooves in a silicon substrate.
• the v-grooves can only be formed in a parallel configuration.
• the gripping elements of the present invention allows for greater flexibility in providing a wider variety of fiber arrangements.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Optical Couplings Of Light Guides (AREA)
• Mechanical Coupling Of Light Guides (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Publications (1)

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Cited By (1)

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• 2002
  • 2002-07-23 US US10/202,513 patent/US20030174943A1/en not_active Abandoned
• 2003
  • 2003-02-28 EP EP03713818A patent/EP1483608A1/en not_active Withdrawn
  • 2003-02-28 AU AU2003217849A patent/AU2003217849A1/en not_active Abandoned
  • 2003-02-28 WO PCT/US2003/006280 patent/WO2003079084A1/en not_active Application Discontinuation
  • 2003-02-28 JP JP2003577033A patent/JP2005520203A/ja not_active Withdrawn
  • 2003-03-13 TW TW092105977A patent/TWI230808B/zh not_active IP Right Cessation

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